Auto starter



J. N. WALKER July 12, 1932.

AUTO STARTER Filed Dec. 11. 1929 2 Sheets-Sheet 1 ATTORNEY J. N. WALKER July 12', 1932.

AUTO STARTER 2 Sheets-Sheet '2 Filed Dec. 11, 1929 ATTORNEY Patented July 12, 1932 UNITED STATES JACOB N. "WALKER, F RICHMOND, VIRGINIA AUTO STARTER- Application filed December 11, 1929. Serial No. 413,319.

This invention relates to improvements in engine starting devices of the type commonly known as self-starters, an object being to provide means for crankinglan internal combustion engine with a minimum amount of shock at the beginning of the cranking operation.

To this end, the invention provides a starting device which is normally disengaged from the engine, and which when operated, will start the operation of the engine, means being included in the starting device to gradually transfer motion from said device to the engine to prevent shock.

With the above and other objects in view,

the invention further includes the following novel features and details of construction, to be hereinafter more fully described, illustrated in the aocompanyingdrawings and go pointed out in the appended claims.

In the drawings 2-- Figure 1 is an-elevation of the invention. Figure 2 is a longitudinal sectional view with the device in its normally inactive posizs tion.

Figure 3 is a like view with active position. I

Figure 4: is a View with the parts in the position shown in Figure 3 and showing other of the parts in section.

Figures 5 and 6 are sectional views taken respectively on the lines 5-5 and 6-6 of Figure 3.

Figure 7 is a fragmentary sectional View showing a modified form of the invention.

Figure 8 is a sectional view showing a further modified form. of the invention. a

Figure 9 is a section on the line 99 of Figure 8.

Referring to the drawings in detail wherein like characters of reference denote corresponding parts, the reference character 10 indicates a barrel-like housing which is provided at one end with a sleeve or extension 12, the latter forming a bearing for one end of the housing. This shaft represents the drive shaft of the device and may be connected or form a part of the shaft of an electric motor or other prime mover.

The sleeve 12 also forms the hub of a pinion the device in 14 which is normally spaced from and adapted to engage the teeth 15 of an engine fly wheel. A stop collar 16 is mounted upon the outer end of the shaft 13. v

The shaft'13 is threaded for a portion of its length as indicated at 17, these threads terminating to provide stops 18 and 19 at opposite ends of the threaded portion.

Mounted for movement upon the shaft 13 is a sleeve 20 which is internally threaded for engagement with the threads 17 and which is provided with a flange 21. Mounted upon this sleeve is a spring 22, one end of which bears against the inner end of the barrel 10 while the opposite end bears against the opposed face of the flange 21, the action of the spring being to yieldingly force the sleeve away from the inner end of the barrel. A spring 23 which is seated within an annular groove provided within the barrel acts to limit relative movement of the barrel and sleeve.

The flange 21 of the sleeve is provide with a lug 24 which is movable within a groove 25 I extending longitudinally within the barrelv so as to prevent relative rotary movement betweenthe barrel and sleeve. A spring influenced pin 26 is carried by a collar 27 which is secured to the shaft 18, and this pin is removably engaged within an opening 28 providedin-the flange 21, so that when the partsare in an active position independent movement of the sleeve upon the shaft-due to vibratiomwill be prevented.

Normally, the parts are arranged as shown inFigure 1 of the drawings with the pinion l tspaced from the toothed fly wheel 15. When the shaft 13 is rotated (through the operation ofv a motoror other prime mover) the sleeve 20, due to its threaded engagement with-the shaft 18 willbe caused to travel inward or to the left of the'figures of the drawings. The force of the spring against the inner end of the barrel 10 will cause this barrel to move longitudinally upon the shaft until the pinion lengages the fly wheel 15. Rotation of the barrel 10 will thus be resisted. Continued movement of the sleeve longitudinally of the shaft will compress the spring until compression 'is sufiicient to provide suflici-ent friction between the flange 21 and the inner end of the barrel to overcome the resistance of the engine. The engine crank shaft will thus begin rotation without sudden shock due to the flexibility of the connection between the sleeve and drum. The degree of compression of the spring necessary to crank the engine depends upon the point at which the engine has stopped. In other words, when the engine crankshaft is. positioned so that the engine will turn over easily, the sleeve 20 will travel only a relatively short distance along the shaft before there is sufficient action to start the engine. g

By reference to Figures 5 and 6 of the drawings it will be seen that the thickness of the barrel varies so as to provide a weighted side- 29, so that the barrel will occupy a position with the tooth 24: downward. In Figure 7, an annular compressible member 30 is substituted for the spring 22. This member is provided adjacent its inner end with a metal- 150 lining 31 so as to prevent undue spreading of the member. In this form of the invention,

when the sleeve 20 moves inward, the member 30 will be compressed to provide the frictional connection before mentioned.

In Figures 8 and 9, the lug 24 and groove 25 are omitted, and the opposite ends of the spring 22 are extended as shown at 32 and 33, for engagement within respective openings 34 and 35 provided in the end of the barrel and in the flange 21. In this form of I the invention, a limited yielding connection is provided between the sleeve and barrel.

By increasing the thickness at the portion 29 of the barrel, the lower portion will be weighted. This will tend to prevent rotation of the barrel at the initial operation of the device so that the teeth of the pinion 14 and fly wheel 15 will more-readily engage.

The invention is susceptible of various changes in its form, proportions and minor details ofconstruction and the right is herein reserved to make suchchanges as properly fall within the scope of the appended claims.

Having described the invention what is claimed is:- v

1. In an engine starting device, a barrel, a spirally threaded driving shaft extending therethrough, a gear affixed to one end of the barrel for engagement with the fly wheel of an engine to be started, a sleeve located within the barrel and havinga fixed abutment thereon, the sleeve being threaded on the shaft, for forward movement thereon when the shaft is rotated, a resilient element surrounding the shaft inside of the barrel and bearing against said abutment and against the inner end of said barrel, and means whereby said sleeve may be telescoped into said barrel, in n0n-rotatable relation therewith, to'compress said resilient element and provide a yielding driving connection between said sleeve and said gear.

2. In an engine starting device, a barrel, a spirally threaded driving shaft extending therethrough, a gear afiixed to one end of the barrel for engagement with the fly wheel of an engine to be started, a sleeve located within the barrel and having a fixed flange thereon, the sleeve being threaded on the shaft, for forward movement thereon when the shaft is rotated, a floating resilient element surrounding the shaft inside of the barrel and bearing against said flange and against the inner end of said barrel, and means whereby said sleeve may be telescoped into said barrel, in non-rotatable relation therewith, to compress said resilient element and provide a yielding driving connection between said sleeve and said gear.

3. In an engine starting device,'a barrel having one side weighted to provide inertia with respect to the shaft, a spirally threaded driving shaft extending through the barrel, a gear afliXed to one end of the barrel for engagement with the fly wheel of an engine to be started, a sleeve located within the barrel and having a fixed abutment thereon, the sleeve being threaded on the shaft, for forward movement thereon when the shaft is rotated, a spring surrounding the shaft inside of the barrel and hearing againstsaid abutment and against the inner end of said barrel, and means whereby'said sleeve may be telescoped into said barrel, in non-rota table relationtherewith, to compress said spring and provide a yielding driving connection between: said sleeve and said gear,

4. In an engine starting device, a barrel, a spirally threaded driving shaft extending therethrough, a gear affixed to one end of the barrel for engagement with the fly wheel of an engine to be started, a sleeve located within the barrel and threaded on the shaft for forward movement thereon when the shaft is rotated, the sleeve and barrel including shouldered portions, a resilient element concentric with the barrel and retained at-opposite ends by the shouldered portions of the sleeve and barrel, and means providingslidable but non-rotatable movement of the sleeve with reference to the barrel, the barrel thereafter advancing with the sleeve.

In testimony whereofI affix my signature. JACOB N. WALKER. 

